1. Field of the Invention
This invention relates generally to fuel control systems for dual fuel engines and, more particularly, to such systems having a lead fuel governing system and a log fuel governing system.
2. Description of the Prior Art
Constant energy input to a dual fuel compression ignition engine is required for consistent and stable operation. Considerable difficulty has been experienced in attempting to maintain constant energy input to dual fuel compression ignition engines during variation of fuel schedule and/or load and/or heat content of supplied fuels. Hence, disturbed and erratic operation of dual fuel compression ignition engines has become a problem whenever one or more of the aforementioned variations are present.
A number of fuel control systems for dual fuel engines have heretofore been proposed. Examples can be found in U.S. Pat. No. 4,278,064 to Regueiro, U.S. Pat. No. 4,489,699 to Poehlman, and U.S. Pat. No. 4,416,244 to McDonald. Each of the foregoing lack features of the present invention, disclosed and claimed herein, which features operate to overcome the problems mentioned in the preceding paragraph, and which, by overcoming those problems, serve to provide a fuel control system for dual fuel engines that is much improved over invention is more flexible than that disclosed in U.S. Pat. No. 4,278,064 as it is capable of handling gases of different heat value and quantities, more variable than that disclosed in U.S. Pat. No. 4,489,699 as it has more selector options, and more totally variable with regard to load than that disclosed in U.S. Pat. No. 4,416,244 as it is not relatively restrictive from the standpoint of control through a variable load range.